Railway-traffic-controlling apparatus



Oct. 29, 1929. H. A. THOMPSON RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Dec. 11, 1926 I cut-W INVENTOR Patented Oct. 29 1929 UNITED STATES PATENT OFFICE HOWARD A. THOMPSON, 0F EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, TION OF PENNSYLVANIA OF SWISSVALE, PENNSYLVANIA, A CORPORA- RAILWAY-TRAFFIG-CONTROLLING APPARATUS Application filed December 11, 1926. Serial No. 154,099.

My invention relates to railway traflic controlling apparatus, and particularly to apparatus of the type comprising train carried governing means adapted to co-operate with train controlling devices located in the track way, the condition of which devices is responsive to traffic conditions. More particularly my present invention relates to the trackway portion of such apparatus.

I will describe one form of railway traific controlling apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of trackway apparatus embodying my invention.

Referring to the drawing, the reference characters 1 and 1 designate the track rails of a stretch of railway track over which traffic normally moves in the direction indicated by the arrow. These track rails are divided, by means of insulated joints 2, to form a plurality of successive track sections AB, BC, etc. Each such section is provided with a source of track circuit current here shown as a battery designated by the reference character F with an exponent corresponding to the location and connected across the rails adjacent the exit end of the associated section through the usual impedance 3. Each section is also provided with a track relay designated by the reference character R with an appropriate exponent and connected across the rails adjacent the entrance end of the corresponding section. It will therefore be seen that each track section is provided with a track circuit including a track relay R, a track battery F, an impedance 3 and the rails of the section in series. Associated with each track relay R is a home relay designated by the reference character H with an exponent corresponding to the location. Each home relay H is normally energized over a stick circuit including its own front contact and a front contact of the associated track relay.

Referring for example, to home relay H the stick circuit for this relay may be traced from a suitable source of energy such as a battery E through wires 9 and 10, front contact 11 of relay H wires 12 and 13, front contact 1 1 of relay R wire 15, resistor 16, wire 17 winding of relay H and wires 18 and 19 back to battery E Each section is also provided with a distant relay designated by the reference character D with an appropriate exponent. The circuit for relay D may be traced from battery E located at point B, through wires 20 and 21, front contact 22 of relay H wires 23 and 24, front contact 25 of relay R wire 26, winding of relay D wire 27, front contact 28 of relay H and wires 29, 30 and 31, back to battery E The circuit for each of the remaining relays D is similar to that just traced for relay D and it follows that each distant relay D is energized only when the associated track relay is energized and when the track relay and the home relay for the section next in advance are also energized.

Each track section is provided with a trackway signal designated by the reference character S with a suitable exponent and as here shown each such signal is located adjacent the entrance end of the corresponding section. The signals S may be of any suitable form and are here illustrated as three-indication light signals, each comprising three light units 6, 7 and 8, arranged when ener gized to displaya stop, a caution or a proceed indication, respectively. Each signal S is controlled by the adjacent home relay H and distant relay D. Referring particularly to signal S when relays H and D are both energized, current from battery E flows through wires 9 and 32, front contact 33 of relay H wire 3 1, front contact 35 of relay D wire 36, unit 8 of signal S and wires 37, 38 and 19 back to battery hen this circuit is closed, unit 8 of signal S is lighted to indicate proceed. If relay D is de-energized, however, the signal S indicates caution, the caution circuitpassing from battery E through wires 9 and 32, front contact 33 of relay H wire 34, back contact 35 of relay E wire 39, unit 7 of signal S and wires 37 38 and 19 back to battery E hen relay H is de-energized, current flows from battery E through wires 9 and 32, back contact 33 of relay H wire 10, unit 6 of signal S and wires 37, 38 and 19, back to battery E a train controlling device here shown as an inductor designated by the reference character K with a suitable exponent Each inductor K is located a short distance in rear of the entrance end of the corresponding section, and comprises a magnetizable core 5 carrying a winding 4. The winding 4 of each inductor K is provided with a path of low resistance which is controlled by the track relay and the distant relay for the associated section'so that when these two relays are both energized the winding is shunted. As shown in the drawing the low resistance paths ofinductors K and K are open but winding 4 of inductor K is shunted through a. circuit which may be traced from the right-hand terminal of winding 4 of this inductor, through wire 41, front contact 42 ofv relay R wires 44 and 44 front contact 45 of relay D and wires 46 and 47, back to the left-hand terminal of winding 4 of inductor K The inductors K are suitable for co-operation with train carried governing means not shown in the drawing but which is responsive'to the effective reluctance of the core 5 of eachi-nductor. In systems of this character the train carried governing means is usually arranged to display a stop indication when the train passes a trackway inductor which has a comparatively low re luctance due to the fact that the low resistance path for winding 4 is open. When the train-passes an inductor the winding 4 off which is shunted however, the comparatively high reluctance of the core 5 prevents the display of a stop indication on board the train.

Since systems of the type described depend,

for their action upon the change in the effective reluctance of the inductor core due to the shunting of theindu'ctor winding, it followsthat it is desirable to provide some check to.- insure the integrity of the inductor windin and its associated circuits. In my present ihvention, l accomplish this. check by pre-' venting the pick-up of the home relay when a train leaves the associated section if there is any defect in the inductor, for such section. Referring particularly to the apparatus located at point B, the relay H is de- H which may be traced from-battery E through wires'20 and 21, back contact 22 of relay H wires 48'and44, front contact 42 of relay R wire 41,, winding 4 of inductor K wire47, backcontact 49 of relay H wires 50 and 17, winding of relay H and wires 18 and 31, back to battery E As soon as relay l l becomes energized the opening of back contacts 49'and 22 opens the pick-upcircuit just'traced, but during the brief interval that this pick-up circuit is closed a sufficient amount of energy is supplied to relay H to close its front contacts, \Vhen this happens the, stick circuitv for relay H is completed, and the relay is subsequently maintained in its energized condition by means of its stick circuit over its own front contact and front contact of relay BR It, will be plain, therefore, that when a train moves out of the section, thehome relay will remain in its de-energized condition if any defect exists in winding 4 of the inductor for the section orin the circuits associated with this inductor. For example, I will assume -hat a break occurs in winding 4 of inductor K Under theseconditions the pick-up circuit for relay 1-1 will not be closed when the train V moves out of section BC. The signal S? will therefore continue to indicate stop and since the circuit for relayD includes afrontcontact of relay H relay D will continue to be de-energized and. signal S will with apparatus embodying my invention, a dangerous condition can-not arise due to a break in an inductor winding or in the circuit associated therewith. One advantage of my invention over apparatus heretofore suggested is that the shunting circuit for the inductor is completely isolated from *the. checking circuit and fromallcontrol circuits for thesignal under normal conditions, the inductor circuit being'checked momenta rily each time the trainleaves the associated sectionj 7 Although I have herein shown and de-" scribed only one form of railway trafic con trolling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departremain at caution. It follows therefore that ing from the spirit and scope of my inven- 1. In combination with stretch of railway track, a relay, a signal controlled by the relay, a trackWay device comprising a Winding, a pick-up circuit for the relay including the Winding, and a stick circuit for said relay entirely isolated from such Winding.

2. In combination, a stretch of railway track, a trackvvay device comprising a Winding, a relay arranged to be de-energized When a train occupies such stretch, a signal controlled by the relay, means effective When such train leaves the stretch to supply current to the relay through said Winding, and a circuit isolated from the Winding for subsequently maintaining the relay in its energized condition.

3. In combination, a section of railway track, a track circuit for the section includinga track relay, a home relay, a distant relay controlled in part by the track relay, a signal controlled by the home and distant relays, a trackway device comprising a Winding, a path of low resistance for said Winding including front contacts of the track relay and the distant relay, a pick-up circuit for the home relay including the Winding and a front contact of the track relay, and a stick circuit for the home relay including a front contact of the track relay and a front contact of the home relay but not including the Winding.

In testimony whereof I aliix my signature.

HOWARD A. THOMPSON. 

